This paper investigates voluntary HIV testing behaviour among young adults in two Cape Town townships. Despite exceptionally high HIV prevalence rates, South Africa experiences low rates of HIV testing. Low levels of testing are worrisome because knowledge of HIV status is thought to be a key element in both the prevention of HIV transmission and the provision of care and treatment for those who are infected. Through qualitative in-depth interviews with 15 young adults (9 female, 6 male), this study found that choices regarding the voluntary uptake of HIV testing were strongly linked to the perceived implications of the HIV test. An analysis of the findings illustrates that study participants perceived HIV positive people to experience a number of threats because of their status – namely physical threats, social threats, and psychological threats – and that HIV testing served to either mitigate or expose an individual to these threats. Physical threats posed by HIV, such as opportunistic infections or death, encouraged HIV testing because it was only through testing that these potential threats could be mitigated. Conversely, an HIV test exposed an individual to social threats, such as ostracism and shame, and psychological threats, such as depression and self-rejection. Where social and psychological threats were perceived to be strong, testing was actively avoided. The findings of this study are that the decision to voluntarily test for HIV can be explained through a balance of the physical, social, and psychological threats that one can mitigate or be exposed to through testing for HIV. Using a threat-balance model, the analysis of findings shows that when study participants perceived physical threats to outweigh perceived social and psychological threats of living with HIV, they were biased towards testing. When they viewed social and psychological threats to outweigh physical threats, they were biased against testing. The focus on perceived threats of living with HIV highlights the need to focus on the social and psychological aspects of HIV/AIDS disease and illness, and not simply the clinical diagnosis and treatment of symptoms, both of which focus on physical threats. Because enhanced infrastructural resources for HIV testing and the availability of ARVs for mitigation of the physical threats alone do not encourage HIV testing, a comprehensive plan to increase HIV testing must also seek to reduce the social and psychological threats presented by HIV infection.